Friction shock-absorbing mechanism



Aug. 14, 1928.

. 1,680,612 s. B. HAsl-:LTINE FRICTION SHOCK ABSORBING MECHAN-ISM Original Filed Sept. 26, 1923 2 Sheets-Sheet ff@ y? Aug. 14, 1928.

S. B. HASELTINE FRICTION SHOCK ABSORBING MECHANISM Original Filed Sept. 26

NR MR mwN s SQ w Patented Aug. 14,1928. l i j i 1,680,612

UNITED STATES PATENT OFFICE.

STACY B. HASELTINE, OF CHICAGO, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS, TO W. H. MINER, INC., A CORPORATION OF DELAWARE.

FRICTION SHOCK-ABSORBING MECHANISM.

Application led September 26,1923, Serial No. 664,867. Renewed December 27, 1927.

This invention relates to improvements in of the drawings the improved shock abfriction shock absorbing mechanisms. sorbing mechanism proper comprises a com- The object of the invention is to provide bined front followerand wedge casting A; a friction shock absorbing mechanism, inthe rear follower casting B; a friction post cluding a central friction post and a wedge C; three friction shoes D-D; three wedge 5:3 pressure transmitting means, wherein is obblocks EEg a. wedge ring F; four stop tained high frictional capacity combined members Gr-G; a spring resistance H; and a with assured release, the arrangement be pair of retainer bolts K. ing such that a high frictional capacity is The combined front follower and wedge 10 developed during compression by a system cast-ing A is of hollow construction and com- 60 of relatively blunt and keen angle wedge prises, a top wall 26; a bottom wall 27 a and friction elements front wall 28; a rear wall 29; and three Other Objects and advantages 0f the inlongitudinally arranged Walls 30 XteIldlUg vencion will more clearly appear from the from the front wall 28 to the rear wall 29, l5 description and claims hereinafter following. the Said walls 30 beingconnected by curved 65 In the (lrmvings, forming a par@ of this web portions 31 and defining a. casing in Specification, Fig l is a, longitudinal, scc. which the wedge friction shoes are housed. tional Vip/V 0f a pal-t, 0f a, railway draft rig- AS Clearly SllOlVIl lll 2,'tl'1e VVIVllS LIG ging, illustrating the preferred form 0f my arranged symmetrically7 about the axis of 20 lnpl-Ovements in Connetio'n therewith, the th@ gll and l1,115 provided at the IOIlt ends 70 section through the follower, friction elethGlOf Wlll lntGFOl, FGFWilI'dly, diverging ments and other parts corresponding to two flat HCQS 32 QXGDCllDg at a relatively keen section planes at approxinjately 120 apart. llllg'le Wltll I'GGIGHCQ il() lngltlldll'lal {IXlS Fig. 2 is a vertical, transverse, sectional view O JElle gear as shown in Fig. l. The front 25 opfesponding Substantially t() the, line Tall Of the CtSlDlllg A lS ilCvllpteC-l t0 lbllt 75 0f Fig, l, Fig, 3 is a. front elevational View the front stop lugs 2l and coact therewith of a wedge ring used in connection with the m f1 Well lUlOWIl m5111116?- mechanism shown in Figs. 1 and 2. And The rear followeleasting B is of general- Figs. 4 to ll inclusive are longitudinal, secly rectangular outline and has integrally au tional views of a portion of the front folformed therewith the friction postC. The so lower and elements associated therewith, at OllOWer B iS provided with arear Wall` 33 one side of the longitudinal center line of the adapted JCO CO-aot With the rear Stop lugs mechanism, each view showing a. different 22, and a spaced web 34 laterally projecting elnbodiment. 0f invention. from the I'Gll' (3nd Of the pOSt 21nd GXtend- In the drawings, 20-20 indicate the usual lng 13211111161 t0 the rear Wall 33 0f the Ol- 85 draft center sills of a car underframe, said lOWeI- sills being preferably of channel cross-sec The friction post C is provided at the tion, and to the inner faces 0f which are 5eforward end thereof with three equally cured front stop lugs 21-21 and rear stop spaced. laterally projecting arms thereby 4o lugs @Q -22, 0f usual construction A pcrproviding three longitudinally extending V- 90 tion of thc draw-bar is indicated at 23, the Shaped friction surfaces, which diverge Same having operatively associated thereslightly in a direction toward the rear of with a hooded cast yoke 24 of well known the mechanism. form. and within which is disposed the shock The three friction shoes D-D, preferably 4:3 absorbing mechanism proper, hereinafter dein the form of castings, are of. like construc- 95 scribed. The yoke and parts contained tion. each having' a. V-shaped inner friction therein are supported in operative position surface 37 adapted to co-act with one of the by ay detachable `saddle plate 25. Vshaped friction surfaces 36 of the post Referring first, to the preferred form of C. Atthe outer side, each friction shoe D 5o the invention illustrated `in Figs. l, 2 and 3 `is provided lwith a face 38 slightly inclined 100 rearwardly andoutwardly with respect to the Vshaped surface 37 therof. At the rear end portion beyond the face 38 each friction shoe D is provided with a rearwardly and f outwardly inclined face 39 extending at a relatively keen angle with reference to the longitudinal axis of the meehanisn.v

The three wedge blocks E, preferably 1n thel foam of castings.A are of like construclfi tion, each having a flat inner side face 40, a flat wedge face 4l at the front end thereof, correspondingly inclined to the face 32 of the follower A, and a fiat wedge face 42 at the rear end thereof rearwardly convergi ing and extending at a relatively blunt angle with reference tothe longitudinal axis of the mechanism. Each ot' the wedge blocks E is interposed between one of the side walls 3() of the follower A. and one of the shoes 'lo D, with the flat face 40 thereof engaging the face 3S of the shoe and the wedge face 4l engaging the adjacent face 32 of the follower A.

The wedge ring F surrounds the friction J-"i shoes D and is interposed between the faces 39 of the latter and the rear ends of the wedge blocks E and is provided with three circumferentially spaced flat faces 48 at the front side thereof, each inclined similarly to Ii" a face 42 at the rear end of one of the blocks E and adapted to coact therewith, and three circumferentially spaced flat faces at the rear end thereof, each inclined correspondingly to the face 39 of one of the shoes D an and adapted to coact therewith. The ring .F is also provided with a laterally project ing circumferential flange 45 at the rear end thereof, the same` being slightly spaced rearwardly of the wall Q9 of the follower A, for

4o a purpose hereinafter described.

The spring resistance H is interposed between tbe web 34 of the rear follower B and the wedge friction shoes D.` having the front end thereof directly abutting the" rear ends 4;'. of the shoes.

y The stop members G are four in number, extending longitudinally of the mechanism and are located at the corners of the followers being slidably mounted between 5i' bosses 47 on the rear follower B and the bosses 48 on the front follower A and eX- tending loosely through alined recesses in the web 34 and the rear wall 29 of the front follower A. The stop members G are of a. such a length that the front ends thereof are adapted to abut the bosses 47 and 48 of the rear and front followers respectively, to limit the relative inward movement of the follower when the gear is fully compressed` au thereby forming in effectstop columns by which the excess pressure is transmitted direetly from .the front follower to the rear follower. In this connection it will be noted that the front wall .28 of the follower A is er. recessed as indicated at 46 to receive the front end of the post C and permit the front Vall of the follower A to pass inwardlyv bcyond the outer end of the post when the gear is fully compressed, the recess 4(3'correspending in outline to the cross-section of the outer end of the post and loosely accommodating the same.

rlhe retainer bolts K are two in number arranged on opposite sides of the gear .mid way of its height, each bolt having the rear end thereof anchored lo the web 34 of the rear follower casting P and its front end anchored to the wall 2S) of the front follower casting A.

The operation of the device shown in Figs. l.y Q and 3 is as follows, assuming a compression stroke of the mechanism. As the front follower is forced inwardly of the gear, a wedging action will be set up between the wedge faces 3Q of the follower A and the wedge faces 41 of the wedge blocks E, and between the wedge faces 44 of the ring l? and the wedge faces $52) of the shoes D, the ring being forced rearwardly substantially in unison with the block E during the initial action on account of the blunt and relatively non-wedging angle of the faces 4L and 43 of the block E and the ring F. It will be evident that rearward movement of the shoes D will be resisted by the spring H during this action. As the parts continue their n'iovement inwardly, the shoes D will slide on the V-shaped friction faces of the post C, and will he gradually separated due to the taper of the friction post. also ell'ecting a gradual slight separation of the wedge blocks E, thereby setting up a difcrentialwvedge action, the faces il and 49. of the blocks E slipping,r on the faces It: and et?, of the follower A and the wedge ring F respectively, and the faces 2li) of the. .shoes D slipping on the faces -14 of the ring l" causing a rearward movement of the shoes D relatively to the wedge blocks E and ilu follower A and, thereby, ell'ecting an additional rearward movement of the shoes D on the post G. This causes a further conipression of the spring H. A slight clearance is left between the side walls il() of the follower A and the wedge blocks E and between the,

shoes D rand the ring F to permit of the necessary lateral movement of the shoes and wedge blocks relatively to the ring and follower respectively.

Upon removal of the compression force initial releasing action takes place on the faces 352 and 41.('if the follower A and the wedge blocks E the follower falling awav from the blocks due to the bluntness of the contacting faces; the pressure on the outer end of wedges E being thereby removed, the latter members on account of the blunt angle included between faces 40 and 42 thereof. relieve themselves from contact with shoes D and ring F, and the whole wedging 'Hifi lli) llfi

Lio

structure collapses, thereby reducing the pressure on the wedge shoes D permitting the spring to move the shoes, ring and wedge blocks outwardly to restore all the parts to normal position.

As wear occurs on the different faces, compensation therefor is had by the shoes E and the ring F moving forwardly, the spring being placed under initial compression when the parts are assembled to assure of this movement, the clearance between the flange 45 of the ring and the rear wall of the follower beingleft to permit forward movement of the ring. The over-all length of the mechanism is maintained substantially constant by the bolts K.

In the different modifications shown in Figs. 4 to 11 inclusive, various arrangements of wedges, wedge shoes and rings are illustrated, associated with a front follower and a post of the character shown in Figs. 1 and 2, the remaining co-operating parts of the mechanism, which are in all respects similar to that shown in Fig. 1 not being shown in these g'ures.

Referring first to the form of theinvention illustrated in Fig. 4, the mechanism shown therein comprises, a front follower A; a friction post C', three wedge friction shoes D; three wedge blocks E', a wedge ring F; and a spring follower' ring M. The follower A is provided with a front wall 128, a rear wall 129, side walls and wedge faces 132, and the post C is provided with arms and V-shaped friction surfaces 136, said parts being in all respects similar to the corresponding parts shown in Fig. 1, there being three wedge faces 132 on the shell and three arms 135 on the post C.

Intel-posed between each of the side walls of the follower A and the post C is a friction shoe D having at its outer side a rearwardly extending face disposed at a relatively keen angle with reference to the longitudinal axis of the mechanism, a fiat outer face 141 at the front end correspondingly inclined to and adapted to co-act with one of the faces 132 of the follower, and a flat face 142 at the rear end thereof extending at a relatively blunt angle-with reference to the axis of the mechanism. The shoes D are surrounded by a. wedge ring F having three circumferentially spaced flat faces at the front side thereof, one of which is shown in Fig. 4 and Ais indicated at 143. The faces 143 are inclined similarly to the faces 140 of the wedge shoes D and are adapted to co-operate therewith. The ring F is also provided with three circumferentially spaced, inner wedge faces at the rear end thereof, one of which is shown at 144 in Fig. 4. The ring F4 is further provided with a flange 145 similar to the fiange 45 of the ring F of the preferred form of the invention, and is spaced from the rear wall of thek front follower for asimilar reason. A wedge block E having the fiat rear face 146 and a pair of rearwardly diverging wedge faces 147 and 148 at tsfrOnt end is interposed between the rear endV of each shoe D and a spring follower ring VM directly engaged by the front end of the spring resistance. The wedge faces 147 and 148 are similarly inclined to and co-act with the wedge faces 142 and 144 respectively of the shoes D and the ring F, and the flat face 146 thereof bears on the spring follower ring.

The operation of the device shown in Fig. 4, is as follows, assuming a compression stroke in the mechanism. As the follower A moves inwardly, the wedge shoes D `will be forced inwardly and at the same time spread apart due to the taper of the post C, a wedging action will be first set up between the keen faces 140 and 143 of the shoes D and the ring F', forcing the shoes into intimate frictional contact with the V-shapedv friction surfaces 13G of the post C, there being only slight slippage between the faces 132 and 141 of the follower A and the shoes D at this time due to the lateral movement of the shoes. During the further inward movement of the follower A the shoes D will further be spread apart due to the taper of the post C', thereby effecting a differential action, the faces 141, 140 and 142 of the shoes D slipping on the faces 132, 143 and 147 of the follower A', ring F" and wedge blocks E', and the faces 144 of the ring F slipping on the faces 148 of the wedge blocks E thereby effecting an increase in length of the wedge friction system and an additional compression of the spring resistance. Upon removal of the compression force, the follower A will drop away from the wedge shoes D and the latter will be forced outwardly with reference to the ringr by the'wedges E', whereupon, all the parts will be restored to normal position by the action of the spring resistance.

VReferring to the modification illustratedV in Fi g. 5, the mechanism shown therein, comprises, a follower A2; a post C2; three wedge friction shoes D2; three wedge blocks E2; and a wedge ring F2.

The post C2 is in all respects similar to the post C of the preferred form, being provided with three arms 235 and three rearwardly diver-ging V-shaped friction surfaces 236, with which three shoes D2 co-act. Each of the shoes D2 is provided with an. outer wedge face 210 at the front end thereof disposed at a relatively keen angle with refer- Sri lee

and 213 being disposed at relatively blunt angles with reference to the longitudinal axis of the mechanism. Each face 213 of the ring F2 also co-'acts with a similarly inclined face 214 .at the rear end of the block E2. The follower' A2 is in all respects similar to the follower A of the preferred form. with the exception that the same is provided with three interior wedge faces Q32, disposed at a more obtuse angle with reference to the longitudinal axis of the mechanism than the corresponding faces of the follower A. Each of the faces Q32 is adapted to co-act with a similarly inclined face Q33 at the outer end of one of the blocks E2, it being understood that there. are three blocks E2, coacting with the three shoes D2 and the follower A2. Rearward movement of the ring F2 is directly opposed by a spring' resistance similar to the spring H.

In the operation of the device shown in Fig. 5. as the follower A2 moves inwardly, the initial action is a wedging between the faces 210 of the shoes D2 and the faces 211 of the wedge blocks D2, forcing the shoes against the friction surfaces Q36 on the post C2, there being substantially no relative movement between the faces Q32 and 233 of the follower and the wedge blocks E2 and between the faces 213 and 214 of the ring F2 and the blocks E2 at this time. This action results in a slight spacing of the faces 213 of the ring with reference to the faces Q12 of the shoes D2, rearward movement of the shoes D2 being resisted, due to the friction between the same and the tapered post C2. During the further movement of the follower A2, the shoes D2 will be moved rearwardly therewith on the post C2 and a slight gradual spreading apart of the shoes will be effeeted due to the taper of the post C2. A differential action is thus produced. the faces 233 and Q14 of the wedge blocks slipping on the faces 232 and 213 of the follower A2 and the ring F2, thereby producing an addition al rearward movement of the shoes D2 and the ring F2. Upon removal of the compression force, the follower will drop away from the block 4 2, and the ring F2 under the inuence of the spring will force theblocks E2 forwardly until the shoes D2 are picked up by the ring, whereupon all the parts will be restored to normal. position.

Referring to the modification illustrated in Fig. 6. the mechanism shown therein comprises a follower A3; a post C3; three wedge friction shoes D2: three wedge blocks E, and a wedge ring F2.

The post C3 is in all respects similar to the post C of the preferred form, being provided with three arms 335 and three V- shaped rearwardly diverging friction surfaces 336 with which the shoes D3 co-act. Each of the shoes D3 is provided with a flat outer side face 310 slightly inclined rearwardly and toward the axis of the mechanism. The three shoes D3 are also provided with laterally projecting lugs 311, each adapted to engage loosely within a corresponding recess 312 in the ring F2, so ar ranged that limited rearward movement of; the ring relatively of the shoes is permitted. rlhe wedge blocks E3 are each provided with a relatively keen wedge face 332 at. the front end thereof, adapted to eo-act with one of the three faces on the shell A and a slightly hlunter face 334e at the rear end thereof adapted to co-aet with a similarly inclined face 335 at the front end of the ring F3, there being three such faces on the ring, one for each block. Rearward movement of the ring F2 is directly resisted by a spring similar to the spring H of the preferred form.

In the operation of the device shown in Figure G, as the follower A3 moves inwardly an initial wedging action is set up lietween the wedge faces 339 of the wedge blocks and the wedge faces 333 of the follower, pressing the wedge blocks E tightly against the shoes and the shoes against. the friction surfaces of the post. During this initial action there is substantially no relative movement between the faces 33st anc 335 of the blocks and ring, the ring being forced rearwardly a slight distance with respect to the shoes D". During the further movement of the fol lower A3 the wedges E3 will slide rearwardly and inwardly on the surfaces 310 of the shoes D2, a slippage occurring between the faces 332 and 334 of the blocks E" and the faces 333 and 335 of the follower A3 and the ring F2 respectively, forcing the ring F2 rearwardly until the front walls of the recesses 312 therein engage the lugs 311 on the shoes D", whereupon the latter will be moved rearwardly tlierewith. During the rearward movement of the shoes, the same will be spread apart gradually due to the taper of the post, effecting a differential action. the faces 332 and 334 of the wedge blocks E slipping on the faces 333 and 335 of the follower and ring respectively, producing an additional rearward n'iovement of the slices D2 and the ring F3, further compressing the spring. Upon removal of the compression force, due to the bluntness of the angle included between the wedge faces of the follower', the latter will drop away from the wedge blocks and the blocks. due to the bluntness of the faces in contact with the ring, will be readily forced outwardly relative to the shoes, relieving the pressure thereon, until the latter are picked up by the ring, permitting the spring to return all of the parts to normal position,

Referring to the modification illustrated in Figure 7, the mechanism shown therein comprises, a follower A4; a post C, three wedge friction shoes D; three wedge blocks llU E4; three auxiliary wedge blocks N4; and a springl follower ring P4.

The post C4 is inV all r'espects similar to the post .C of the preferred forni being provided with three arms 435 and three rearwardly diverging V-shaped friction surfaces 436 with which the shoes D4 coact. Each of the shoes D4 is provided with a lateral projection 410 having a front wedgeV face 411 and a rear wedge face 412 adapted to coact respectively with a rear wedge face 413 on the inner side of one of the wedge blocks E4 and a front wedge face 414 on the inner side of one of the auxiliary wedge blocks N 4, the faces. 411 and V413 extending at arelatvely keen angle and the faces 412 and 414 extending at a relatively -blunt angle with reference to the longitudinal axis of the mechanism.` The outer side of each block E4 is also cut away at the rear endthereof to provide a flat face 419 correspondingly inclined to and adapted to coact with the face 414 of the corresponding `block N. Each, of the blocks E4 is provided with a fiat front face 420 adaptedto coact with one of tlnee flat vertical faces 421 on the inner side of the follower A4. Each of the wedge blocks N4 is provided with a relat-ively-keenangle face 415 at the front end thereof adapted to coact with one of three corresponding inclined inner faces 416 at the rear en'd of the follower A4. Each of the blocks N4 is further provided with a slightly beveled rear face 417 adapted to abut one of three correspondingly beveled faces 418 on the spring follower ring P4. Rearward movement of the ring P4 is directly resisted by a spring similarly arranged to the spring H of the preferred forni of the invention. i

rl`lie operation of the device shown in Figure 7 is as follows, assuming a compression stroke of the mechanism. As the follower A4 moves inwardly, a wedging action will be setup between` the faces 4413 and 411 of the blocks E4 and the shoes D4 `and the shoes moved rearwardly on the post C4. During this rearward movement the shoes will be gradually spread apart due to the taper of the post C4 thereby setting up a differential ywedge action, the faces 419 and 42() of the blocks E4 slipping on the faces 414 and 421 of the blocks i 4 and the follower A4 respectively forcing the blocks N4 to slide on the flat faces 416 of the shelhand effecting a separation of the faces 414 and 412 of the shoes D4 and block N4, the rear ends of the blocks N4 being held in roper position during this time due to tie coacting beveled faces 417 and 418 on` the blocks andring respectively. Upon removal o f the compression force, due to the separation existing between the slices D4 and blocks N4, the wedges are projected forwardly directly by the blocks N4, actuated by the full reactive force of the springs, thereby relieving the wedge .vided with three arms 5 5 wardly diverging V-shaped friction surfaces comprises, broadly, a follower A5';\a frictionr post C5 three friction slices D5; three wedge blocks E5; three auxiliary blocks M5; and a springl folloiiei'P5.

The post C5 is in all respects similar to the post C of the preferred form, being proand three rear- 536 with which the three shoes D5 coact.

I Each ofthe shoes D5 is provided with.i an

outer wedge face 51() at the front end thereof disposed at a relatively keen angle with reference to the longitudinal axis of the mechanism and cti-operating with a similarly inclined face 511 on the inner side of one of the. three blocks E5. Each shoe is also provided with a face 512 to the rear of the face 510 cooperating with a flat wedge face` ferred form. The blocks E5 are each provided with an outer relatively blunt wedge face 533 at the front end thereof adapted to coact with onev of three similarly inclined inner wedge faces `532 of the follower. The ring P5 is adapted to coact with a spring similar to the spring H and is provided with three circumferentially spaced apart outer beveled faces at the front side thereof adapted to coact with similarly beveled faces on the blocks M5. u v

The operation of the device shown in Figure 8 is as follows, assuming a. compression stroke of the mechanism. As the follower A5 moves inwardly a wedging action will be set up between the faces 510 and 511 of the shoes D5 and the blocks E5 and the shoesV will be moved rearwardly on the post C5. During this rearward movement the shoes `will be gradually .spread apart dueto the taper ofthe post C5, thereby setting up a differential wedging action, the faces 533 of the blocksE5 slipping onthe faces 532 ofthe follower and the faces 514 of the blocks E5 slipping on the faces 513 of the'blocks M5 thereby effecting a rearward movementof the shoes with reference to the follower, and a rearward movement of the blocks l 5 with reference. to the shoes D5 as well asa gradually increasing clearance between the faces 513 of the blocks M5 and the faces 512 of the shoes D5. A further rearward movement of the blocks M5 will also be effected due to the converging faces 530 of the follower. The beveled contacting faces on the ring P5 and the blocks M5 serve to maintain the blocks in contact with the converging faces 530 of the follower.

Upon removal of the compression force, on account of the clearance existing between shoes D5 and wedges M5, the entire outward force of the spring is exerted against the wedging system in such manner as to break up the close contact between the various members of same, allowing these members to readily be moved outwardly, thus relieving the frictional resistance on the Shoes, the latter being picked up and moved outwardly when contact is restored between same and the wedges M, all the parts being thus re' turned to their normal positions.

Referring to the modification illustrated in Figure 9 the mechanism shown therein comprises, a follower A6; a friction post C6; three friction shoes D6; three wedge blocks E6; and a follower ring P6.

The follower A6 is somewhat similar to the follower A of the form of invention shown in Figures 1 and 2, with the exception that the former is provided with additional wedge faces at the inner end portion thereof. The follower A6 is provided with three walls 63() and three wedge faces 632 extending at a relatively keen angle to the axis of the mechanism, and three additional wedge faces 640 at the inner end portion thereof extendingl at a relatively keen angle to said axis. The post C6 is in all respects similar to the post C, being provided with three arms 635 and three rearwardly diverging V-shaped friction surfaces 636.

The friction shoes Da cooperate with the friction surfaces 636, each shoe being provided with a front wedge face 633 coacting with one of the wedge faces 632 of the follower and a rear wedge face G34 coacting with a correspondingly inclined wedge face 645 on the front end of the corresponding block Ee and extending at a relatively blunt angle with reference to the axis of the mechanism. Each of the blocks E6 is provided with a flat outer side face corresponding in inclination to and adapted to slide on one of the faces 640 of the follower. The ring P surrounds the rear ends of the shoes D and is provided with three circumferentially spaced, beveled faces G37 on the front side thereof adapted to coact with correspondingly beveled faces on the rear ends of the blocks E to hold the latter in contact with the flat inner surfaces of the follower. Rearward movement of the ring P is resisted by a spring similar to the spring H.

'The operation of the device shown in Figui-e9 is asifollows, assuming a compression stroke of the mechanism. As the follower A0 moves inwardly a wedging action is set up between the faces 632 of the follower and the faces 633 of the shoes and between the faces G3i of the shoes and the facesbl of the blocks E, pressing the shoes against the post C and the blocks E6 against the faces 640 of the follower. During further movement of the follower AG the shoes D will be moved rearwardly on the post C and spread apart slightly due to the taper of the post, the spreading of the shoes ell'ecting a -diil'erential wedge action, the faces G33 and 634: of the shoes D6 slipping on the surfaces G32 and 645 of the follower A and the blocks E6 respcctviely and the blocks E slipping on the faces 640 of the follower. The shoes D are thus moved rearwardly with reference to the follower and the blocks moved rearwardlyv with reference to the shoes. Upon removal of the compression force, the reactive force of the `spring is exerted outwardly against the ring P, restoring all the parts to normal postion, the angularity of the co-acting wedge faces of the follower A and the shoes D6 and wedge blocks F c being such that the follower A will readily drop away.

Referring to the modification illustrated in Figure 10, the mechanism shown coniprises, a follower A7; a friction post C7; three friction shoes D7; three wedge blocks E7; three auxiliary wedge blocks R7; and a spring follower ring P.

The post C7 is in all respects similar to the post C of the preferred form, being provided with three arms 735 and three rearwardly-divcrging V-shaped friction surfacesl 736 adapted to slidingly receive the shoes D7. Each of the shoes D7 is provided with a laterally projecting lug 740 at the rear end thereof provided with a flat front face 741 extending at a relatively blunt angle with reference to the longitudinal axis of the mechanism. Each of the shoes D1 is also provided with a fiat longitudinally extending side face 742 slightly inclined rearwardly and outwardly with reference to the co1'- responding face 736 of the post CT. 'l` he faces 741 are adapted to co-act with blunt inner faces 744 on the auxiliary blocks R" and the faces 742 are adapted to coact with correspondingly inclined faces 743 on the wedge blocks E7. The follower A" has the side walls thereof provided with three front and three rear inner wedge faces 745 and 746 respectively, all disposed at relatively keen angles with reference to the axis of the mechanism. Each of the faces 746 is adapt ed to coact with a similarly inclined outer face T48 at the front end of one of the blocks R7.y The wedge blocks E7 are each provided with a front wedging face 747 adapted to abut one of the faces 745 of the follower A" and 'with a rear outer face/749 adapted to abut ashort inner wedge face 750 disposed at a relatively blunt, angle with reference to the axis of the mechanism, at the front end of the adjacent block R7. The ring T7 bears directly on the rear faces of the lugs 740 and rearward movement thereof is resisted by a spring similar to the spring H of the preferred form.

The operation of the device shown in Figure 10 is as follows. As the follower A7 moves inwardly a wedging action is setup between the wedge faces 745 and 747 of the follower A7 and the blocks E7, thereby pressing the shoes D7 against the post C7. As the follower A7 moves inwardly, the shoes D7 will be forced gradually outwardl due to the taper of the post C7, thus setting up# a differential action in the wedge blocks E7, causing the latter to slip outwardly along the surfaces 745 and 747. At the same time a slippage occurs along the faces 749 and 750 of the blocks E7 and R7 respectively, thus forcing the latter rearwardly and outwardly between the faces 7 46 of the follower and 741 of the shoes D7, Vwhich are thereby carried still further rearwardly, a slippage occurring between the faces 742 and 7 43 of the shoes and wedges E7, as the. wedging mechanism is thus elongated. Upon removal of the compression force the followed A7 will fall away from the wedges E7 and R7 thus relieving the pressure on the latter and the Shoes D7, permitting the spring resistance to restore all the parts to normal position.

Referring to the modification illustrated in Figure 11 the mechanism shown therein comprises a follower A8, a friction post C8;

three friction slices DS; three wedge blocks E8; and wedge ring TB; and a spring follower ring P8.

The follower A8 and the post C8 are in all respects similar to the follower A and the post C of the preferred form of the invention, the follower A8 being provided with three longitudinal walls 83() and three interior wedge faces 832; and the post being provided with three arms 835 and three rearwardly diverging V-shaped friction surfaces 886. The shoes D8 are each adapted to slide on one of the surfaces 836 of the post, and each is provided with a laterally projecting lug 840 at the rear end thereof having a. flat front face 841 extending at a relatively bluntl angle with reference to the longitudinal axis of the mechanism. Each of the shoes D8 is also provided with a fiat longitudinally extending side face 842 slightly inclined rearwardly with reference to the corresponding side face 836 of the post C8. The faces 842 are adapted to coactwithflat inner side faces 843 on the blocks E8 and the faces 841 are adapted to coact with correspondingly inclined faces 844 on the ring T8. Each of the faces 832 of the follower A8 is adapted to coact with a similarly inclined face 833 at the front end of one of the blocks B8. these faces being disposed at a relatively keen angle with reference to edge of the wedge ring T8, the faces 845..

and 846 being inclinedV at relatively blunt angles with reference to the longitudinal axis of the mechanism. The wedge ring TS,

and the blocks E8, as shown, are spaced .from

the walls 830 of the follower A8. The ring P8 bears directly on the rear faces of the lugs 840 of the shoes DS and rearward movement thereof is resisted by a spring .similar to the -spring H shown in Figures 1 and 2.

The operation of the device shown in Figure 11 is as follows. As the follower AS moves inwardly a wedging action is set up between the wedge faces 832 and 833 of the follower and the blocks E8 respectively thereby forcing the blocks E8 against the shoes Ds and pressing the shoes against the post CS. As the follower A8 moves inwardly, the wedge blocks ES will force the wedge ring TS rearwardly, the latter, in turn, through engagement with the lugs 840 on the shoes D8 forcing the shoes rearwardly also. As the shoes move rearwardly on the friction surfaces of the post C3 they will be gradually spread apart due to the taper of the post, forcing the wedge blocks E8 outwardly also, thereby effecting a differential wedge action, the faces 833 slipping on the faces 832 of the follower, the faces 845 slipping on the faces 846 of the ring TS andthe faces 841 of the shoes DS slipping on the faces 844 of the ring T8. The shoes D8 will thus be forced rearwardly relatively to the follower A8, and thewedges E8, a slippage thus occurring between the faces 842 and 843 of the shoes and the blocks E7. Upon removal of the kcompression force, the follower AS will drop away from the wedges E8 thus relieving the pressure on the latter and the shoes D8, permitting the spring resistance to restore all the parts to normal position.

I have herein shown and described what I now consider the preferred manner of carrying out the invention, but thesame is` merely illustrative and I contemplate all changes and modifications that come within the scope of the claims appended hereto.

I claim:

1. In a friction shock absorbing mechanism, the combination with a tapered central friction element; of a series of friction lshoes co-operable with said element; a spring resistance; a plurality of wedge blocks having engagement with the shoes; and a wedge pressure transmitting means having wedging engagement with said blocks; a wedge ring co-operating with said blocks, said blocks and ring having co-acting sets of faces which are disposed at a relatively blunt non-Wedging angle with reference to the longitudinal axis of the mechanism.

loo

member; .e Wedge ring and Wedge blocks, said ring and block havingV cooperating faces disposed at u relatively blunt non-edging angie with reference to the longitudinal exis of the mechanism.

In witness that I claim the foregoingr I have hereunto subscribed .my nume this 22nd day of September, 1923.

STACY B. HASELTINE. 

